Tooth-forming potential in embryonic and postnatal tooth bud cells.

Humans are genetically programmed to replace their teeth once during childhood. Therefore, when adult teeth are lost or damaged, they cannot be regenerated or regrown. However, with the advancement of stem cell biology and tissue engineering, regenerating the whole tooth has become a realistic and attractive option to replace a lost or damaged tooth, and therefore has strongly attracted attention in the field of dental research. During the past several years, significant progress has been made in this research endeavor, providing greater understanding of the production of an entire biological tooth by tissue engineering using stem cells. There are several ways to reproduce an entire biological tooth. Approaches are categorized according to the cell sources that have the potential to produce teeth. One source is the embryonic tooth bud, and the other is the postnatal tooth bud. The results from embryonic and postnatal tooth buds differ considerably. In particular, the potential to regulate the shape of the tooth crown from embryonic tooth bud is higher than from postnatal tooth bud. This article describes the achievements to date in production of biological teeth, mostly from our laboratory. In particular, we describe the potential to produce teeth from embryonic and postnatal tooth buds.